Locking pliers are well known in the art. These devices typically include two jaws that may be locked about an object. The locking is effected by forcing two handles together wherein the handles cooperate to form an over center mechanism.
For example, U.S. Pat. No. 6,578,452 shows a vise grip locking tool that contains jaws that are capable of opening with a flick of the user's wrist. The tool comprises a first handle member, a second handle member, a lower jaw, and an upper jaw. The first handle member is pivotally attached to the lower jaw. The first end of the lower jaw is made up of four mutually interconnected sides having a guided slot extending through it. The upper jaw has an elongated shank that may slide along the guided slot of the lower jaw. A stop is present on the bottom of the shank preventing the upper jaw from escaping the guided slot. The second handle member is pivotally mounted to the lower jaw and includes a releasable lock which is made up of a spring operated detent which engages teeth on the elongated shank.
U.S. Pat. No. 5,357,829 illustrates pliers having opposed gripping tips thereon wherein each gripping tip is figured as a tooth that extends toward the opposite gripping tip.
U.S. Pat. No. 5,022,290 discloses a locking pliers wrench having a first handle member having a first jaw member lockable at a plurality of positions relative to the handle member and removable from the handle member. Different jaw members having different length shanks may be substituted. A second jaw member is pivotally mounted on and straddles the handle member.
U.S. Pat. No. 3,672,245 shows pliers for positively gripping a selected workpiece between substantially parallel gripping jaw surfaces. One of the jaw surfaces is carried by a fixed handle. The other is carried by a pivoted toggle member mounted on an extension of the fixed handle for pivotal movement and adjustment toward and away from the jaw surface on the fixed handle.
U.S. Pat. No. 3,241,410 consists of a combination quick set and vise grip wrench wherein toggle action levers in the handles pivotally urge an elongate shank and associated moveable jaw toward a stationary jaw with gripping action.
U.S. Pat. No. 2,905,038 describes a toggle wrench with slidable adjustment. The wrench comprises a vice grip or quick set type which employs an over center mechanism.
U.S. Patent Application Number U.S. 2003/0221523 depicts an adjustable pliers wrench including a fixture having a handle and an opposing stationary jaw, a coacting jaw pivoted to the fixture, and a lever pivoted to the coacting jaw. A guide is attached proximate the handle and a locking element is arranged on the guide for reciprocal and canting movement. At least one attached biasing element urges the locking element toward the stationary jaw. An arm is pivoted to the lever and a cam is pivoted to the arm and to the locking element so as to be movable between a first condition permitting the locking element to reciprocate along the guide and a second condition bearing against the guide and canting the locking element into frictional engagement against the guide.